All contemporary cochlear implant systems require two separate components: (1) an implant that is implanted in the skull, and (2) a sound (or speech) processor that resembles a hearing aid and is worn on the outside of the body. The two components are linked through RF communication, and operating power for the implant is supplied by the sound processor and transmitted inductively.
The power source in the sound processor consists of either rechargeable or primary batteries. Typical battery operating times for current cochlear implant systems are between 4 hours and 3 days. When battery power is depleted, the cochlear implant user has to physically remove the empty battery from the sound processor and replace it with a new one. This creates several problems:                (1) The small size of the batteries requires good manual dexterity for changing them, which is a problem especially for the many cochlear implant users who are elderly.        (2) Batteries are a choking hazard for small children.        (3) Cochlear implant users have to carry spare batteries with them at all or most times.        (4) The sound processor has to contain a battery compartment that can be either removed entirely for recharging, or that has to have a mechanical latch or door for replacement of the batteries. The mechanical components required increase the size of the processor, and contribute a potential failure mechanism.        
It is thus apparent that what is needed is a sound processor for use with a cochlear implant system, or other hearing-aid system, that avoids or minimizes the above-problems.